This invention relates to admixtures or additives for concrete and mortar obtained by sulphonation of petroleum processing residues. It relates particularly to low foaming admixtures capable of functioning as, among other things, either water reducers or superplasticizers in concrete.
Water reducers either reduce the water requirement for a cement, mortar, or concrete mix without reducing the required initial workability, thus increasing the compressive strength, or increase the workability of a cement, mortar or concrete mix without increasing the water requirement. The superplasticizers also reduce water requirements, but permit much higher levels than is possible with normal water reducers, since they possess low surfactant properties which permits them to be added at much higher dosages without adverse effects due to air entrainment. Superplasticizers also typically have very high liquefying or plasticizing action, providing much higher workabilities. They are, however, much more expensive than normal water reducers. The normal water reducers are typically low cost lignosulphonatebased materials while superplasticizer formulations are based on more sophisticated manufacturing processes incorporating sulphonated melamine or naphthalene and formaldehyde.
U.S. Pat. No. 3,277,162 describes a dispersant obtained from the products of condensing formaldehyde with naphthalene sulphonic acid. U.S. Pat. No. 3,970,690 describes dispersants obtained from the products of sulphonation of the residues of from thermal cracking of petroleum oil. In U.K. Patent 2,159,536 a sulphonated dispersant is obtained from the products of sulphonation of tars. A dispersant obtained by the sulphonation of a petroleum asphalt fraction is described in U.S. Pat. No. 5,322,556.
It is an object of the present invention to produce relatively inexpensive admixtures for concrete, from the sulphonation of hydrocracked petroleum residues, which will exhibit strong deflocculation characteristics without significantly lowering the surface tension of water. This combination would allow the admixture of this invention to perform as both a water reducer and a superplasticizer, resulting in not only a lower priced superplasticizer, but further economy due to the elimination of storage and dispensing equipment for a separate water reducer, and would provide better quality control due to the wider range of water reduction available, and a decrease in the number of concrete ingredients.